class Solution {
public:
    /**
     * 
     * @param strs string字符串vector 
     * @return string字符串
     */
    string longestCommonPrefix(vector<string>& strs) {
        if (strs.empty()) {
            return "";
        }
        string res;
        for (int i = 0; i < strs[0].length(); ++i) {
            char c = strs[0][i];
            for (auto &s : strs) {
                if (i >= s.length() || s[i] != c) {
                    return res;
                }
            }
            res += c;
        }
        return res;
    }
};

思路:以第一个字符串为基准,遍历strs并判断每个字符就行了。